1. Field of the Invention
This invention relates to medical diagnostic and therapeutic methods and, in particular, to a method for cannulating a retinal blood vessel such that a medication may be injected or a quantity of fluid removed from the blood vessel. Alternatively, a catheter, wire or stent may be placed through the cannula to treat or diagnose an area remote from the insertion site.
2. Description of Related Art
The cannulation of a retinal blood vessel is difficult as the lumen of the blood vessels is less than 200 microns in size. The present day ocular instruments are too large to cannulate the vessel and the dexterity required to maintain the cannula within the blood vessel for several minutes is not commonly available. The piercing of a blood vessel elsewhere in the body to inject medications, perform surgical procedures or remove blood for analysis and treatment is commonly performed. It is therefore, to the effective resolution of the aforementioned problems and shortcomings that the present invention is directed.
Accordingly, it is an object of this invention to provide a microcannula or micropipette whose lumen is small enough to be safely placed within the lumen of a retinal blood vessel and by its configuration is parallel to the lumen when placed through a standard sclerotomy site, as commonly used in vitreoretinal surgery. The terms microcannula and micropipette are used interchangeably throughout the application. To the extent that such terms differ in any way in meaning, if any, then the broadest definition of the two terms is considered to be the definition for both terms for purposes of the instant invention disclosure.
It is another object of this invention to provide, by its configuration and method of attachment, a stable support such that the micropipette may be securely held within the blood vessel so that subsequent maneuvers may be safely accomplished.
It is still another object of this invention to provide a micromanipulator such that the micropipette may be remotely advanced to perforate the retinal blood vessel.
It is yet another object of this invention to provide a portable device that may be easily attached to a standard operating surgical wrist rest and is stable in its “X”, “Y” and “Z” planes.
It is a further object of this invention to provide a device that, by its configuration and method of attachment, does not inhibit the surgeon's view when using an operating microscope or otherwise interfere with the use of the operating microscope.
It is yet another object of this invention to provide a safe method such that the surgical procedure may be performed.